Three dimensional print head apparatus

ABSTRACT

A three-dimensional print head apparatus may include a securing mechanism, a hopper, a nozzle, a heating system, and a fume extraction system. The securing mechanism may be adapted to secure to a wrist joint of a robotic arm. The hopper may have a cavity and a lower aperture and may be secured to the securing mechanism. The nozzle may have an upper aperture and a lower aperture. The heating system may be positioned along the barrel.

RELATED APPLICATIONS

This application is a continuation application of and claims priorityunder 35 U.S.C. § 120 of U.S. patent application Ser. No. 16/656,743(Attorney Docket No. 6270.00016) filed on Oct. 18, 2019 and titled PRINTHEAD FOR REGOLITH-POLYMER MIXTURE AND ASSOCIATED FEEDSTOCK. Thisapplication also claims priority under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application Ser. No. 62/777,315 (Attorney Docket No.89.00079) filed on Dec. 10, 2018 and titled POLYMER CONCRETE WITHTHERMOPLASTIC AS BINDER. This application also claims priority under 35U.S.C. § 119(e) of U.S. Provisional Patent Application Ser. No.62/756,904 (Attorney Docket No. 89.00080) filed on Nov. 7, 2018 andtitled ADDITIVE MANUFACTURING PRINT HEAD FOR REGOLITH-POLYMER MIXTURES.This application also claims priority under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application Ser. No. 62/747,184 (Attorney Docket No.89.00084) filed on Oct. 18, 2018 and titled CONCRETE PELLET FEEDSTOCKFOR 3-D AUTOMATED ADDITIVE CONSTRUCTION. The contents of theseapplications are incorporated herein by reference except to the extentthat the content therein conflicts with the content herein.

GOVERNMENT INTEREST

The invention described herein was made in the performance of work undera NASA contract NNK11EA08C and by employees of the United StatesGovernment and is subject to the provisions of Public Law 96-517 (35U.S.C. § 202) and may be manufactured and used by or for the Governmentfor governmental purposes without the payment of any royalties thereonor therefore.

FIELD OF THE INVENTION

The present invention relates to systems and methods for additivemanufacturing. Specifically, the present invention is related to a 3Dprint head mechanism that can be attached to a robotic positioningdevice for three-dimensional automated additive construction. may be

BACKGROUND OF THE INVENTION

Prior art methods of construction use sulfur-based concretes as buildingmaterials. Sulfur is not available on the Moon in large quantities.In-situ resource utilization (ISRU) is an essential technology toaccomplish putting humans on the Moon or Mars for extended durations.Therefore, there exists a need for an apparatus utilizing in-situresources to construct structures on the Moon or Mars.

Portland cement concrete is the standard material for construction onEarth with over one hundred years of history promoting public trust. Alarge-scale 3D printer may be utilized to print using Portland cementconcrete as the printing medium. While a printing operation usingPortland cement concrete is feasible, there is a lot of preparation andcleanup work associated with using Portland cement concrete as theprinting medium. In addition, using Portland cement concrete, therheology is critical at a nozzle extrusion point and materialscomposition and mixing is also critical to achieving a successful printbead. Many in the construction industry have expressed a preference touse Portland cement concrete because it can be purchased locally almostanywhere in the world, thereby simplifying logistics when buildingstructures globally. There exists a need for a printing medium andapparatus that promotes consumer confidence and produces a strongerproduct using a less complicated 3D printing method for construction oflarge structures such as habitats.

This background information is provided to reveal information believedby the applicant to be of possible relevance to the present invention.No admission is necessarily intended, nor should be construed, that anyof the preceding information constitutes prior art against the presentinvention.

SUMMARY OF THE INVENTION

With the above in mind, embodiments of the present invention are relatedto a three-dimensional print head apparatus that may include a securingmechanism, a hopper, a nozzle, a barrel, a heating system, and a fumeextraction system. The securing mechanism may be adapted to secure to awrist joint of a robotic arm. The hopper may be secured to the securingmechanism and may have a cavity and a lower aperture. The nozzle mayhave an upper aperture and a lower aperture. The heating system may bepositioned along the barrel.

The heating system may include a heating device that may be in thermalcommunication with the barrel, a thermocouple that may be in thermalcommunication with the barrel, and a heating controller that may be inelectronic communication with the heating device and the thermocouple.The heating controller may activate the heating device dependent upon aninput signal received from the thermocouple. The heating system may alsoinclude an insulator located on an external side of the barrel.

The hopper may include an upper hopper plate configured to carry thesecuring mechanism, a conical body that has an upper aperture that mayhave a diameter greater than a diameter of the lower aperture, and alower flange that may be secured to the conical body of the hopperproximate the lower aperture of the conical body. The conical body maytaper from the upper aperture to the lower aperture, and the upperhopper plate may occlude the upper aperture of the conical body.

The upper hopper plate may include an air filter aperture formed througha thickness of the upper hopper plate and may be adapted to carry an airfilter, and a sealable aperture formed through the thickness of theupper hopper plate and may be adapted to be in a sealed or an unsealedconfiguration.

The nozzle may include a tube defining a cavity and may have an open enddefining the upper aperture and an occluded end. The lower aperture ofthe nozzle may be located in the occlude end of the tube.

The fume extraction system may include a plate secured to the nozzle.The fume extraction system may further include a plurality of tubes witheach of the plurality of tubes having a first open end secured to theplate, and a manifold carrying a second open end of each of theplurality of tubes. The fume extraction system may still further includean exhaust tube that may have a first open end secured to the manifoldand in fluid communication with the second open ends of each of theplurality of tubes.

The fume extraction system may also include a cooling fan secured to theplate. The cooling fan may be in fluid communication with the loweraperture of the nozzle. The fume extraction system may further include aduct boost fan that may be secured to the exhaust tube and that may bein fluid communication with an interior volume of the exhaust tube.

The barrel may include a small cone, an upper flange and a pipe. Thesmall cone has a sidewall, an upper aperture, and a lower aperture. Thediameter of the upper aperture may be greater than a diameter of thelower aperture, and the sidewall may taper from the upper aperture tothe lower aperture. The upper flange may be secured proximate the upperaperture of the small cone and may be secured to the lower flange of thehopper. The pipe may have a first end and an opposing second end and maybe secured proximate the lower aperture of the small cone, with thefirst end secured to the upper aperture of the nozzle.

The barrel may further include a feed screw, a drive shaft, a motor, anda motor controller. The feed screw may be positioned in an interior ofthe pipe. The drive shaft may be adapted to transmit torque to the feedscrew. The motor may be adapted to provide torque to the drive shaft.The motor controller may be adapted to control the torque provided bythe motor.

The barrel may yet further include an agitator, a flange, and a ballbearing housing. The flange may be located at a first end of the driveshaft and may be secured to the agitator. The ball bearing housing maybe surrounding the drive shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the present invention are illustrated as an exampleand are not limited by the figures of the accompanying drawings, inwhich like references may indicate similar elements.

FIG. 1 is a perspective view of the 3D print head mechanism according tothe present invention in combination with a robotic arm.

FIG. 2 is a perspective view of the 3D print head mechanism illustratedFIG. 1.

FIG. 3 is a cross section of the 3D print head mechanism taken throughline 3-3 of FIG. 2.

FIG. 4 is another perspective view of the 3D print head mechanism ofFIG. 1.

FIG. 5 is a top perspective view of the 3D print head mechanism of FIG.1 having portions cut away.

FIG. 6 is a bottom perspective view of the 3D print head mechanism ofFIG. 1.

FIG. 7 is a schematic block diagram of the heating system of the 3Dprint head mechanism of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Those ofordinary skill in the art realize that the following descriptions of theembodiments of the present invention are illustrative and are notintended to be limiting in any way. Other embodiments of the presentinvention will readily suggest themselves to such skilled persons havingthe benefit of this disclosure. Like numbers refer to like elementsthroughout.

Although the following detailed description contains many specifics forthe purposes of illustration, anyone of ordinary skill in the art willappreciate that many variations and alterations to the following detailsare within the scope of the invention. Accordingly, the followingembodiments of the invention are set forth without any loss ofgenerality to, and without imposing limitations upon, the claimedinvention.

In this detailed description of the present invention, a person skilledin the art should note that directional terms, such as “above,” “below,”“upper,” “lower,” and other like terms are used for the convenience ofthe reader in reference to the drawings. Also, a person skilled in theart should notice this description may contain other terminology toconvey position, orientation, and direction without departing from theprinciples of the present invention.

Furthermore, in this detailed description, a person skilled in the artshould note that quantitative qualifying terms such as “generally,”“substantially,” “mostly,” and other terms are used, in general, to meanthat the referred to object, characteristic, or quality constitutes amajority of the subject of the reference. The meaning of any of theseterms is dependent upon the context within which it is used, and themeaning may be expressly modified.

An embodiment of the invention, as shown and described by the variousfigures and accompanying text, provides an apparatus forthree-dimensional (3D) automated additive construction, which is alsoreferred to as 3D printing with concrete, mortar, basalt, or other rockbased composite types of materials. Specifically, a 3D print headmechanism 100 that can be attached to a robotic positioning device suchas a robotic arm 200, which may have a wrist joint 201, or a gantrysystem is disclosed.

The 3D print head mechanism 100 heats and extrudes a regolith-polymermixture as part of an additive manufacturing process. The process isintended to use in-situ resources on the Moon or Mars as raw materialsfor large scale construction projects including, but not limited to,habitats, radiation shields, berms, walls, paved surfaces, or the like.The 3D print head mechanism 100 may be mounted to a large robotic arm200, which, alone or in combination with a wrist joint 201, may be thepositioning device for the 3D print head mechanism 100.

The 3D print head mechanism 100 in combination with the robotic arm 200and optional wrist joint 201 may provide an autonomous method ofconstruction on the Moon, Mars, or other celestial body using localresources. This approach may advantageously minimize launch mass ofconstruction materials and reduce human involvement with constructionactivities.

Additive construction technology using in-situ materials from planetarysurfaces may reduce launch mass, allow structures to be threedimensionally printed on demand, and may allow building designs to betransmitted digitally from Earth and printed in space. This mayultimately lead to elimination of reliance on structural materialslaunched from Earth.

The 3D print head mechanism 100 may hold and extrude a regolith andpolymer mixture in a fused deposition modeling additive manufacturingprocess. The regolith and polymer mixture, or other print media, may beplaced in a hopper 106 through a sealable aperture 115, which providesaccess to a volume within the hopper 106. After being placed in thehopper 106, the print media may travel out of the hopper 106 through alower aperture and along a heated barrel 107 to be extruded through anopening 140 in a nozzle 108. The robotic arm 200 or wrist joint 201 mayposition the opening 140 of the nozzle 108 to deposit the print media ina desired location or orientation. The robotic arm 200 or wrist joint201 may dynamically reposition the opening 140 of the nozzle 108throughout the printing process to construct the desired design.

The 3D print head mechanism 100 may by carried by a robotic arm 200,alone or in combination with a wrist joint 201, which may cooperativelyprovide two, three, or more degrees of freedom. The potential degrees offreedom may include movement along the X, Y, and Z axes and rotationabout the X, Y, and Z axes. The robotic arm 200 may be secured to awrist joint 201, which may be cooperatively configured with the roboticarm 200 to position a lower aperture, or opening 140, of the nozzle 108with two, three, or more degrees of freedom. In some embodiments, therobotic arm 200 may provide lateral movement while the wrist joint 201may provide rotation. The movement of the robotic arm 200 may positionthe 3D print head mechanism 100 around the print volume. The 3D printhead mechanism 100 may include a securing mechanism 151, a feeding andconveying system, a heating system, a fume extraction system, and a dryair purge system.

The feeding and conveying system may include a hopper 106, a barrel 107,a nozzle 108, a motor, a transmission, and an agitator 120 and may bedesigned to move raw materials from the hopper 106, through the heatingzone of the barrel 107, and out of the nozzle 108.

The securing mechanism 151 may secure to a wrist joint 201 of a roboticarm 200 or to a robotic arm 200 directly. The securing mechanism 151 mayalso secure to the hopper 106. The securing mechanism 151 may be amounting plate or other mounting hardware providing a rigid connectionbetween the 3D print head mechanism 100 and the robot moving the 3Dprint head mechanism. In one embodiment, the securing mechanism 151 maybe an elongate structure to which the robotic arm 200 or wrist joint 201may be clamped. More specifically, any structure to which the wristjoint 201 or the robotic arm 200 may be secured may be the securingmechanism 151.

The hopper 106 may store the raw materials and be configured to supplythe raw materials to the barrel 107, which may then provide the rawmaterial to the nozzle 108, through which they may extruded.

The hopper 106 may include an upper hopper plate 114, which may carrythe securing mechanism 151 and secure to the robotic arm 200. By way ofexample, and not as a limitation, the upper hoper plate 114, may besecured to the robotic arm with one or more bolts, clamps, welds, or thelike. In one embodiment, the upper hopper plate may secure to the wristjoint 201 of the robotic arm 200 or to the robotic arm 200 using asecuring mechanism 151. The upper hopper plate 114 may have a sealableaccess port, or aperture, 115 and a filter carrying aperture 131. Thesealable aperture 115 may be formed through a thickness of the upperhopper plate 114 and adapted to be in a sealed or unsealedconfiguration. The sealable aperture may be in the unsealedconfiguration to introduce raw materials to the hopper 106 and in thesealed configuration to retain the raw materials within the hopper 106.In one embodiment, the sealable aperture 115 may be secured, or sealed,in a closed configuration while the 3D print head mechanism is in use.The filter carrying aperture 131 may be formed through an entirety ofthe thickness of the upper hopper plate 114 and configured to carry anair filter. The air filter may be removable and replaceable. In oneembodiment, the air filter may be a HEPA filter.

The hopper 106 may include a hollow conical body 130. The hollow conicalbody 130 may be adapted to carry or store the print media. By way ofexample, and not as a limitation, the hollow conical body 130 may besecured to the upper hopper plate 114 with one or more bolts, or thelike. The conical body 130 of the hopper 106 may have an upper aperture,which may be covered, or occluded, by the upper hopper plate 114. Theupper aperture may have a diameter greater than a diameter of a loweraperture of the conical body 130. Walls of the conical body 130 maytaper from the upper aperture to the lower aperture. The conical body130 may taper at a constant slope. In one embodiment, the conical body130 may have a 65-degree slope angle defining an interior cavity whichdecreases in diameter from an upper portion of the hopper 106 to a lowerportion of the hopper 106. The slope angle of the interior cavity may begreater than the angle of repose for the primary raw material of theprint media and may be configured to assist in promoting the movement ofprint media from the upper portion of the hopper 106 to the lowerportion of the hopper 106. The upper hopper plate 114 may have asealable access port 115 which may be unsealed, or opened, to access acavity of the hopper 106. Print media may be introduced to the hopper106 through the sealable aperture 115. The sealable aperture 115 may besealed, or closed, to retain print media within the cavity of the hopper106 and prevent print media from entering or exiting the upper apertureof the hopper 106.

The lower portion of the conical body 130 may have a lower flange 132extending outwardly from an exterior surface of the conical body. Thelower flange 132 may surround a lower aperture of the hopper 106, whichprovides a passageway into the interior of the barrel 107. The lowerflange 132 may secure to an upper portion of the barrel 107. In oneembodiment, by way of example, and not as a limitation, the lower flange132 may secure to an upper flange 117 of the barrel 107 using aplurality of bolts or the like.

A first end of the barrel 107 may be secured to the lower aperture ofthe hopper 106 and a second, opposing end of the barrel 107 may besecured to an upper aperture of the nozzle 108.

The barrel 107 may include a small cone 116 and an upper flange 117,which may be located at an upper portion of the barrel 107. The upperflange 117 may be located above the small cone 116, may extend outwardlyfrom an exterior surface of the barrel 107, and may secure to a lowerportion of the hopper 106. In one embodiment, the upper flange 117 maysecure to the hopper 106 using a plurality of bolts or the like. In oneembodiment, the lower flange 132 of the hopper 106 may secure to theupper flange 117 of the barrel 107 with a plurality of bolts. Both thelower flange 132 of the hopper 106 and the upper flange 117 of thebarrel 107 may include a hole pattern. Each respective hole pattern maybe configured to align with the other hole pattern when the hopper 106is placed adjacent the barrel 107. Such a cooperative design may allowthe hopper 106 to be secured to the barrel 107 by inserting a fastenerthrough the aligned hole patterns.

The small cone 116 of the barrel 107 may be located beneath the upperflange 117 or may have the upper flange 117 secured to an upper,exterior surface. The small cone 116 may have an interior cavity definedby a sidewall tapering from a larger diameter at a top portion of thesmall cone 116 to a smaller diameter at a bottom portion of the smallcone 116. The small cone 116 may have an upper aperture at a top portionof the small cone 116. The upper aperture has a diameter greater than adiameter of a lower aperture located at a bottom portion of the smallcone 116. The diameter of the small cone 116 may taper from the upperaperture to the lower aperture. The interior surface of the small cone116 may have a slope angle equal to the slope angle of the hopper 106.The upper flange 117 may be secured to the small cone 116 proximate theupper aperture of the small cone 116. A pipe 109, which may be anelongate, hollow member, may have a first end secured to a bottomportion of the small cone 116 proximate the lower aperture. In oneembodiment, the pipe 109 may be welded to the small cone 116. In oneembodiment, by way of example, and not as a limitation, the pipe 109 maybe a schedule 80 steel pipe.

The motor may be connected to a feed screw 110 through a transmission.The transmission may include a motor controller, drive shaft 112, andball bearing housing 134. The feed screw 110 may be positioned in theinterior of the pipe 109. The feed screw 110 may be actuated by themotor or a gearbox, which may cause rotation of the feed screw 110,which movement may facilitate the feeding of the print media down thelength of the pipe 109 from the hopper 106 to the nozzle 108. A driveshaft 112 may transmit torque to the feed screw 110. In one embodiment,the torque may be supplied to the drive shaft 112 by a motor. The motormay be controlled by a motor controller, which may provide velocitycontrol in a closed loop to the rotation of the feed screw 110. Themotor controller may also be configured to provide over currentprotection. The motor controller may control the torque provided by themotor to the feed screw 110 through the drive shaft 112. The motorcontroller may receive feedback data indicative of the speed of rotationof the feed screw 110 and may increase or decrease current to the motorin response to that feedback.

The drive shaft 112 of the transmission may have a first end connectedto or driven by the motor, may extend through a pass-through hole in thecenter of a wrist joint of the robotic arm 200, continue into the hopper106, and have a second end secured to the feed screw 110.

The feed screw 110 may secure to the drive shaft using female and malehex features on the drive shaft adapter and feed screw 110.

A ball bearing housing 134 may be secured to and carried by the hopper106. By way of example, and not as a limitation, in one embodiment, theball bearing housing 134 may be secured to the upper hopper plate 114with a plurality of bolts or the like. The ball bearing housing 134 maybe sealed to prevent the raw materials or other substances from enteringthe ball bearing housing 134 or otherwise contaminating ball bearingscarried by the ball bearing housing 134. The ball bearing housing 134may surround the drive shaft 112 to prevent the drive shaft 112 fromcausing unnecessary friction with the hopper 106. Angular contact ballbearings 135 may be pressed into the ball bearing housing 134 andadapted to contact the drive shaft 112. The angular contact ballbearings 135 may react to thrust and radial loading of the drive shaft112.

The drive shaft 112 may include a flange 136, which may be welded to thebottom of the drive shaft 112. The flange 136 of the drive shaft 112 maysecure to an agitator 120. In one embodiment, by way of example, and notas a limitation, the flange 136 of the drive shaft 112 may secure to aflange 139 of the agitator 120 using one or more bolts.

The agitator 120 may include one or more lateral members 137, one ormore paddles 121, one or more upright members 138, and a flange 139. Theagitator 120 may rotate with the drive shaft and break up or fluidizethe bulk material at the bottom of the hopper 106. In one embodiment,the flange 139 of the agitator 120 may secure to one or more uprightmembers 138. The one or more upright members 138 may secure at a firstend to the flange 139 of the agitator 120, extend downwardly from theflange 139 toward the nozzle 108, and secure to a lateral member 137 atthe second end. Each lateral member 137 may secure to an upright member138 at a first end, extend outwardly, orthogonally from the uprightmember 138 toward the conical body of the hopper 106 and secure to apaddle 121 at the second end. In one embodiment, each lateral member 137may secure to a different paddle 121. There may be the same number ofpaddles 121 and lateral members 137. In one embodiment, there may be twopaddles 121. Each paddle 121 may be positioned parallel to an interiorsurface of the conical body 130 of the hopper 106.

Rotation of the drive shaft may cause rotation of the agitator 120 andfeed screw 110. This may cause the raw material of the print media toflow into the flutes of the feed screw 110 and be conveyed down thebarrel 107. The print media may reach the heated zone on the barrel 107,which may melt and mix the raw materials of the print media.

As the raw materials proceed down the barrel, they may enter a heatedzone located along at least a portion of the barrel 107. The heated zonemay be identified as an area of increased temperature along the barrel107. The heated zone may be controlled by the heating system 103, whichmay include a heater 124, which may be resistive heating wires or thelike, wrapped around at least a portion of the barrel 107, one or morethermocouples 125, insulation 126, and a heating controller 152.

The heater 124 may be in thermal communication with the barrel 107 toincrease the temperature of the barrel 107 and melt the print media asit travels down the feed screw 110 along the length of the barrel 107before being extruded through the opening 140 of the nozzle 108. In oneembodiment, the heater 124 may be wrapped around or in thermalcommunication with a bottom portion of the barrel 107. In oneembodiment, the heater 124 may be wrapped around or in thermalcommunication with approximately twelve inches of the barrel 107. Insuch an embodiment, the heater 124 may be resistive heating wires. Oneor more thermocouples 125 may be located along at least a portion of thelength of the heated zone. The one or more thermocouples 125 may be inthermal communication with the barrel 107 or heater 124 and inelectrical communication with a heating controller 152. The heatingcontroller 152 may also be in electronic communication with the heater124. The heating controller 152 may activate or deactivate the heaterdependent upon an input signal received from the thermocouple 125. Theheating controller 152 may activate the heater 124 until a desiredtemperature is detected by the thermocouple 125 at the barrel 107 orheater 124. When the desired temperature is achieved, the heatingcontroller 152 may deactivate the heater 124 until a minimum temperatureis detected by the thermocouple 125 at the barrel 107 or heater 124. Theheating controller 152 may then activate the heater 124 again until thedesired temperature is detected. By toggling on and off the heater 124,the heating controller 152 may maintain a set temperature along theheated zone of the barrel 107. The heated zone may be surrounded by aninsulator 126 placed around the exterior of the barrel 107, one or morethermocouples 125, and heater 124. In one embodiment, the insulation 126may be furnace batting insulation.

The temperature of the heated zone may be controlled by a heatingcontroller 152. The heating controller 152 may receive feedbackindicative of the temperature of the barrel 107, pipe 109, or rawmaterial entering, in, or exiting the heating zone. The heatingcontroller 152 may increase, decrease, or maintain the current orvoltage provided to the heater 124 to achieve a desired temperature.

The pipe 109 may be temperature controlled by the heating system, whichmay create a heated zone along at least a portion of the pipe 109. Theraw materials of the print media may be melted and mixed as theyprogress through the heated zone of the pipe 109 and towards the nozzle108.

In one embodiment, a lower portion of the pipe 109 may include a matingportion 141. By way of example and not as a limitation, the matingportion 141 may be a threaded NPT male interface or the like. Again, byway of example and not as a limitation, the threaded NPT male interfacemay be one inch. The mating portion 141 of the pipe 109 may secure to acorresponding mating portion 142 of the nozzle 108.

The raw materials of the print media may be driven downward through thepipe 109 by the feed screw 110 and be deposited into a cavity 123 of thenozzle 108. The continuous flow of raw materials from the barrel 107 mayfill up the cavity 123 and force the raw materials out of the nozzle 108opening 140.

A nozzle 108 may secure to the barrel 107 and include a mating portion142, a tube 150 defining a cavity 123, an opening 140, and a threadedbolt hole pattern 143. A mating portion 142 of the nozzle 108 may belocated on an upper portion of the tube 150 and configured to secure tothe mating portion 141 of the pipe 109 of the barrel 107. By way ofexample and not as a limitation, the mating portion 142 may be athreaded NPT female interface or the like. Again, by way of example andnot as a limitation, the threaded NPT female interface may be one inch.The 3D print head mechanism 100 may be operated with and compatible withnozzles 108 having varying opening 140 diameters. In one embodiment, thenozzle 108 opening 140 diameter may range from 1/4″ to 15/16″. Thenozzle 108 may have an upper aperture defined by an open end of the tube150. The upper aperture may form a passageway between the nozzle 108 andthe barrel 107. The tube 150 may have an occluded end opposing the openend. The lower aperture, or opening 140, of the nozzle 108 located inthe occluded end of the tube 150 may provide a passageway for the printmedia to exist the 3D print head mechanism 100.

The nozzle 108 may include a pipe cap 146. The pipe cap 146 may belocated on the occluded end of the tube 150. The pipe cap 146 mayocclude the occluded end of the tube 150. By way of example, and not asa limitation, the pipe cap 146 may be steel or the like. In oneembodiment, the mating portion 142 may be located at an open end of apipe cap 146 and the opening 140 may be formed in the occluded end ofthe tube 150 by creating a lower aperture in the pipe cap 146. By way ofexample and not as a limitation, the pipe cap 146 may be a 1″ NPT steelpipe cap. The pipe cap may have an open end and an occluded end. Theopening 140 may be a hole formed along the central axis of the occludedend of the pipe cap of the nozzle 108, the opening 140 may have aninternal or external chamfer. In some embodiments, the opening 140 ofthe nozzle 108 may include both an internal and external chamfer.

The interior portion of the tube 150 between the open end and theoccluded end and within the walls of the tube 150 may be the cavity 123of the nozzle 108. Melted print media may enter the cavity 123 throughthe pipe 109 secured to the open end of the nozzle 108 and exit throughthe opening 140.

The nozzle 108 may include a plate 148 having a threaded bolt holepattern 143 secured to an exterior of the lower portion of the nozzle108 under the opening 140. The threaded bolt hole pattern 143 may belocated on a plate 148, which is may be affixed to an external surfaceof the nozzle 108. The threaded bolt hole pattern 143 may interface witha corresponding bolt hole pattern 147 of the fume extraction system,which may be located on a bracket 118 of the fume extraction system. Thebracket 118 of the fume extraction system may secure to the plate 148 ofthe nozzle 108 using the corresponding bolt hole patterns 147, 143. Thebracket 118 of the fume extraction system may secure flexible tubes 144or cooling fans 145 of the fume extraction system proximate and in fluidcommunication with the opening 140 of the nozzle 108. In one embodiment,the tubes 144 may have an open end secured to the plate 148. The tubes144 may each have an inlet positioned proximate the opening 140 of thenozzle 108 to facilitate removal of gases associated with materialsextruded from the nozzle 108. In embodiments with a plurality of tubes144, each of the plurality of tubes 144 may have an open end secured tothe plate 148. The gases may travel through the tubes 144 to an exhaustremoved from the area in which an operator may be located. A manifold128 may carry second open ends of each of the plurality of tubes 144 anda first open end of an exhaust tube 129. The second open ends of each ofthe plurality of tubes 144 may be in fluid communication with the firstopen end of the exhaust tube 129 at the manifold. The exhaust tube 129may receive gas or fluid from each of the plurality of tubes 144 andexhaust the gas or fluid away from the area in which the 3D print headmechanism 100 is located. One or more cooling fans 145 may be positionedproximate an inlet to each tube 144 to encourage gas or fluid to enterthe tube 144. The cooling fans 145 may be located within an inlet of thetube 144 and configured to draw air and gases from the raw material intothe tube 144. The cooling fans 145 may be located proximate the opening140 of the nozzle 108 to cool the print media after it is extruded.

The fume extraction system may be used to exhaust any fumes producedduring the extrusion process to the outdoor environment for personnelsafety reasons. The fume extraction system may include one or more tubes144 attached near the nozzle 108 opening. The tubes 144 may be flexibleair hoses or the like. The one or more tubes 144 may extend from thenozzle 108 opening 140 along the barrel 107 and the hopper 106 to amanifold 128. The manifold 128 may be configured to combine the airwayof one or more tubes 144 into a single airway of an exhaust tube 129having a diameter larger than the individual tubes 144. In oneembodiment, there may be three two-inch tubes 144, which the manifold128 combines into a single four-inch air hose 129. The air hose 129 maybe routed away from the manifold 128 along the robotic arm 200 and thenoutside to an exhaust chimney. One or more duct boost fans 153 may bepositioned within the tubes 144, 129 and may be used to draw air throughthe air tubes 144, 129 from the nozzle 108 opening 140 to the exhaust. Aduct boost fan 153 may be secured to at least one of the tubes 144, 128and in fluid communication with an interior volume of the same tube.

The dry air purge system may be used to eliminate moisture in the airinside the hopper 106. The dry air purge system may be used to preventmoisture absorption into the pellets when polyethylene terephthalate(PET) based pellets or other moisture sensitive materials are used as acomponent of the raw material. The dry air purge system may include ahigh efficiency particulate air (HEPA) filter 149 carried by the filtercarrying aperture 131, which may be built into the hopper 106. Air mayexhaust from the hopper 106 into the ambient environment through theHEPA filter 149. The HEPA filter 149 may be carried by the upper hopperplate 114. Cleaned and dried ambient air may be forced into the hopper106 by the dry air purge system to provide a continuous supply of dryair at no greater than five psi. The ambient air may be regulated at afacility port. A fan may be configured proximate an inlet of the hopper106 to provide the dry air to the interior of the hopper 106.

The 3D print head mechanism 100 may be adapted to utilize at least twotypes of print media for printing. In one embodiment, the primary rawmaterial of the print media may be powdered black point-1 (BP-1) basaltregolith simulant mixed with high density polyethylene (HDPE). The HDPEmay be in powder or pellet form. In another embodiment, the primary rawmaterial may be pelletized basalt glass fibers mixed with polyethyleneterephthalate glycol (PETG). Regolith is readily available on planetarysurfaces and HDPE can be synthesized from resources in space (especiallyMars) using the Fischer-Tropsch method or recycled from availablemission materials such as packaging. PETG and basalt glass fiber pelletsmay have numerous advantages including excellent material properties andprocessing characteristics.

The robotic arm 200 used to position the 3D print head mechanism 100 maybe a commercially available FANUC M-410iC/185 palletizing robot. This isan industrial robot designed for high volume production to palletizeheavy products quickly and efficiently. The FANUC M-410iC/185palletizing robot has four axes and a payload capacity of 185 Kg (407lbs.). The three major axes (X, Y, and Z) can be moved at speeds up to140°/s and the rotation axis at the wrist joint 201 can move at 305°/s.The maximum reach height of the robotic arm is 314 3mm (124 inches). Thecontrol system may be a Fanuc R-30iB A-Cabinet Controller with a graphiciPendant.

Software utilized to control the robotic arm 200 and attached 3D printhead mechanism 100 may include the following functions: provide a GUIfor all operation and configuration of the software tool; parse theg-code and extract G1 commands containing motion or extrusion into atoolpath array; allow the user to shift the extruded print media to theappropriate robot tool frame; place the extruded print media in anylocation in the robots workable area; complete a safety check to ensurethat the print area does not exceed a defined work area; allow a user toconfigure the following parameters: X, Y, and Z center, print speed,movement speed between extrusions, termination type of motion,acceleration value, feed system motor speed, pause times when startingand stopping extrusion, and enable/disable extrusion control; provide anoption to display a 3D plot of the compiled toolpath; generateappropriate analog output values and pause commands to controlextrusion; compile the resulting program into a valid TP program; allowthe user to save and load configurations for later use; display totalprint size and estimated print time; convert G-Code to proprietary teachpendant programs; extract all motion and extrusion information fromG-Code; allow user to shift the coordinates to the desired robot toolframe; modify commands to include custom motion between extrusions forcleaner print results; and generate a 3D plot of the toolpath forverification.

In order to control extrusion speed and allow the starting and stoppingof extrusion during the print, control hardware may be required. Anadjustable analog voltage output may be connected to an analog input onthe motor controller. The motor controller may be set to an analogvelocity control mode, and the voltage range of the adjustable analogvoltage output may be mapped to a corresponding motor speed. By changingthe analog output value during each print program, the extrusion speedmay be controlled.

Moisture absorbed by the raw materials of the print media, including,but not limited to, the BP-1/HDPE, basalt glass fiber/PETG, or like, maynegatively affect the performance of the system. BP-1 is hygroscopic.Therefore, during the extrusion process, as the BP-1 heats up, themoisture may be liberated and flow to the cooler raw materials above theheated zone. The buildup of moisture in the hopper 106 may cause changesto the characteristics of the raw materials and make the print mediamore cohesive. This may tend to block the flow of raw materials down thefeed screw 110, thereby leading to inconsistent extrusion rates.

The basalt glass fiber/PETG pelletized feed stock may readily absorbwater, which may lead to steam pockets forming in the heated zone of thebarrel 107. The steam pockets may lead to the extrusion rate becominginconsistent. Additionally, PETG may hydrolyze when melted in thepresence of moisture, which may yield a more brittle extrudate.

For these reasons, it may be important to reduce or eliminate excessmoisture within the hopper 106. Thorough pre-drying of the raw materialsand maintaining a dry environment in the hopper 106 while printing maybe sufficient to eliminate issues with moisture in the raw materials.

It may be desirable to have a feed screw 110 with dual flight screws andthin flights to reduce friction experienced by the feed screw 110 andthe related torque supplied by the feed screw motor.

Small changes in the temperature of the nozzle 108 may dramaticallychange the surface characteristics of the extrudate. Factors affectingthe temperature of the nozzle 108, may include, but are not limited to,the heat zone temperature, extrusion rate, environmental temperature,air flow over the nozzle, insulation position, and extrudate buildup onthe nozzle 108. The temperature variations may produce three typicalconditions of the system. When the nozzle 108 is too cold, the rawmaterial may freeze in the nozzle 108 and reduce the effective nozzlediameter. When the nozzle 108 is too hot, the extrudate may adhere tothe nozzle 108 as it flows through, thereby creating a rough extrusion.When the nozzle 108 temperature is just right, the extrudate may flowwith a smooth surface finish and consistent diameter. Therefore, in someembodiments, there may be a second closed loop controlled heating zoneon the nozzle 108 to reduce or eliminate temperature fluctuations withinthe nozzle.

The raw materials may be in powder form or pelletized. Quality andconsistency of extrusions from compounded pellets may be better thanmixed powders.

Important factors to consider when selecting an appropriate robotic arm200 may include, but are not limited to, increased degrees of freedomfor more advanced additive construction techniques, a robust API,communications options for driving the robot, and low-level access torobot functionality. Additionally, direct control or editing of toolpaths may be beneficial.

The quality of print results may be improved by fine tuning factors,including, but not limited to, temperatures, extrusion speeds, printspeeds, and material selection and composition.

A polymer concrete material may be used as raw material, or print media,for three-dimensional automated additive construction. The polymerconcrete material may include granular material and thermoplastics foruse in construction and fabrication applications. The polymer concretematerial is comparable to Portland cement concrete in compressionstrength and up to 6 x stronger in bend strength.

The polymer concrete material may be suitable for several fabricationmethods including injection molding, pouring slabs, machining, 3Dprinting, and additive construction. The polymer concrete material mayhave several unique qualities. One such quality may be that structuresconstructed from the polymer concrete material may be bound to oneanother or repaired using heat. By way of example, and not as alimitation, bricks constructed from polymer concrete material may bebound together using heat. Additionally, and again by way of example andnot as a limitation, heat may be used to repair structural defectsincluding, but not limited to, cracks. The polymer concrete material maybe reheated, which may allow the defective area to be smoothed over.Additionally, the polymer concrete material is substantially impermeableto water and can be made using recycled plastics.

The polymer concrete material may provide the capability to completeconstruction and fabrication projects on the Moon and/or Mars usinglocal resources. This may reduce required launch mass because at least aportion of construction materials will not need to be transported fromEarth. The polymers used in the polymer concrete material may berecycled and/or produced from other material used on the Moon or Mars.Additionally, the granular materials used in the polymer concretematerial may be available on the Moon and Mars.

In addition to uses on Mars or the Moon, the polymer concrete materialis a versatile material that could be used in many other applicationsincluding, but not limited to, civil structures, structural parts,including, but not limited to, wheels or beams, or the like.

The use of polymer concrete material provides a beneficial advantage tooff Earth and remote on Earth construction projects because it may beused with local granular material, or dirt, and recycled plastics. Thismay reduce logistics required to complete construction projects.

Structures constructed from the polymer concrete material may be postprocessed by sintering, which removes the polymers from the structureand sinters the granular material together to form a sintered rockstructure.

The polymer concrete material may be thermoplastic and may havecommercial applications wherever concrete is used, especially in remoteareas where normal Portland cement concrete ingredients may not beavailable. Additionally, the polymer concrete material has potentialcommercial applications where its beneficial properties, including, butnot limited to, simple binding and repair using heat or waterimpermeability are desirable. Because the polymer concrete material maybe produced using local granular materials and plastics in the recyclestream, it has the potential to be less costly than other concretevarieties.

The polymer concrete material may include or comprise basalt andplastic. The basalt may be loose fine basalt powder, such as volcanicash. The plastic may be ground high-density polyethylene (HDPE). Boththe basalt and plastic may be commercially available. The basalt may bemixed with the plastic to create the polymer concrete material. Thebasalt and plastic may be mixed inside a material delivery hopper 106using an agitator 120 paddle 121. The mixture of basalt and plastic maybe moved down a barrel 107 using an feed screw 110.

In another embodiment, the basalt and plastic may be formed intopellets. Each pellet may be comprised of basalt and plastic. By mass,each pellet may be, for example, between 60% and 90% basalt with thebalance percentage as plastic, i.e., between 40% and 10% plastic. Eachpellet, however, may be preferably 85% basalt and 15% plastic by mass.The basalt and plastic may be combined as a single consolidated andthoroughly mixed pellet. In one embodiment, each pellet may be ⅜″ long,and 3/16″ in diameter. The pellets may be fed into a 3D printing systemvia a commercially available pellet conveying system, which may bereferred to as a feeder. The feeder may continuously keep the pellethopper 106 full. The pellet hopper 106 may provide the pellets to anozzle 108. The pellets may enter the nozzle 108 from the hopper 106 bytraveling down a barrel 107 housing a feed screw 110. The outside of thebarrel 107 may be heated using heaters 124 tied to a control system. Theheaters 124 may heat the pellets above the melting temperature of theplastic, which may be 150° C. After passing through the barrel 107, thepolymer concrete material may be extruded by a nozzle 108 as a verythick liquid. The polymer concrete material extruded by the nozzle 108may form a layer on a flat plate. The layer may be ¼″ tall and formed inthe shape in which the nozzle 108 places the polymer concrete material.The nozzle 108 may be raised off the flat plate an additional ¼″ eachtime it prints on top of the previous layer. In this way, the next layeris deposited directly on top of the previous layer. This process may berepeated until the desired completed part height is achieved. The nozzle108 may pre-heat the previous pass to near the plastic meltingtemperature just in front of the print head stream of the next layer,which may facilitate bonding between the two layers.

The print media may be formed into a pellet to be used as the mediumwith which the 3D printer prints. A pellet may include a Portland cement(PC) or other polymer concrete, rock, sand, and thermoplastic polymerbinders formed into a pellet, which may be extruded by the 3D print headmechanism 100.

The PC concrete, rock, sand, and thermoplastic polymer composition maybe formed into 3 mm length pellets. The composition may form pellets byusing a thermoplastic polymer binder, which may, more specifically, bean anhydrous thermoplastic polymer binder with glass fiberreinforcements. The pellets may be 3D printed by extruding these pelletsout of a heated nozzle 108 of a 3D print head mechanism 100. In oneembodiment, the desired structure may be achieved by placement of thepellets by a 3D printer, which may not heat the pellets prior toextrusion. In such an embodiment, the structure may be saturated withsprayed water after the pellets are placed. The water may activate thePC chemical reaction and harden the PC into PC concrete.

Using pellets with an anhydrous thermoplastic binder and glass fiberreinforcements provides a superior method for 3D printing PC whencompared to a method of 3D printing using PC slurry concrete. WhilePortland cement slurry concrete 3D printing is possible, it is verymessy and hard to control. Labor costs and complexity of design can bereduced when the pelletized concrete printing method is employed.Additionally, use of the pellets is more practical for roboticautomation of the PC 3D printing process. Pelletized printing isadvantageously clean and precise. Water is added as a post curing stepin order to harden the concrete into its final state, thereby providinga cleaner printing process.

Additionally, complex shapes can be formed with a non-heated 3D printhead using the pellets, which are not possible with traditional concreteform work or brick laying. Use of the pellets also allows automation andprecise 3D printing of Portland cement concrete, which is not possibleusing a slurry. An additional benefit to the use of pellets compared toa slurry is less material is needed as pellet designs can useadvantageously optimized hollow structures, which are not possible withslurry.

The pellet may provide particular benefits when used to create large 3Dprinted structures. The pellets may include sand, rock, and a polymerbinder in addition to the PC concrete. All of the elements in themixture may be formed into a pellet and extruded by a 3D printer as theprinting medium. The pelletization of the sand, rock, and cement mayincrease the versatility of the concrete. The sand, gravel, and cementmay be ground into a powder form along with the polymer binder, mixedhomogenously, and formed into a pellet.

The concrete may be Portland cement concrete or another similar type ofconcrete. The rock may be a crushed rock aggregate. The sand may be ageneral purpose sand. The polymer binder may be an anhydrousthermoplastic polymer binder with glass fiber reinforcements. Generally,it may be desirable to use as little of the polymer binder as possiblein the mixture. The mixture may, for example, have a 3:2:1 ratio ofgravel, sand, and cement with additional polymer binder mixed in assmall an amount as necessary to pelletize the gravel, sand, and cement.In one embodiment, 25% of the entire mix may be a polymer binder. Insuch an embodiment, the mixture may have a 3:2:1:2 ratio of gravel,sand, cement, and polymer binder. Each of the four ingredients may befinely ground to a find ground powder. The mixture may then bepelletized into pellets of 3 mm or less length.

Some of the illustrative aspects of the present invention may beadvantageous in solving the problems herein described and other problemsnot discussed which are discoverable by a skilled artisan.

While the above description contains much specificity, these should notbe construed as limitations on the scope of any embodiment, but asexemplifications of the presented embodiments thereof. Many otherramifications and variations are possible within the teachings of thevarious embodiments. While the invention has been described withreference to exemplary embodiments, it will be understood by thoseskilled in the art that various changes may be made, and equivalents maybe substituted for elements thereof without departing from the scope ofthe invention. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventionwithout departing from the essential scope thereof. Therefore, it isintended that the invention not be limited to the particular embodimentdisclosed as the best or only mode contemplated for carrying out thisinvention, but that the invention will include all embodiments fallingwithin the scope of the appended claims. Also, in the drawings and thedescription, there have been disclosed exemplary embodiments of theinvention and, although specific terms may have been employed, they areunless otherwise stated used in a generic and descriptive sense only andnot for purposes of limitation, the scope of the invention therefore notbeing so limited. Moreover, the use of the terms first, second, etc. donot denote any order or importance, but rather the terms first, second,etc. are used to distinguish one element from another. Furthermore, theuse of the terms a, an, etc. do not denote a limitation of quantity, butrather denote the presence of at least one of the referenced item.

Thus the scope of the invention should be determined by the appendedclaims and their legal equivalents, and not by the examples given.

The claims in the instant application are different than those of theparent application or other related applications. Applicant thereforerescinds any disclaimer of claim scope made in the parent application orany predecessor application in relation to the instant application. Anysuch previous disclaimer and the cited references that it was made toavoid, may need to be revisited. Further, any disclaimer made in theinstant application should not be read into or against the parentapplication.

What is claimed is:
 1. A three-dimensional print head apparatuscomprising: a securing mechanism adapted to secure to a wrist joint of arobotic arm; a hopper secured to the securing mechanism and having acavity and a lower aperture; a nozzle having an upper aperture and alower aperture; a barrel; a heating system positioned along the barrel;and a fume extraction system.
 2. The apparatus of claim 1 wherein theheating system comprises: a heating device in thermal communication withthe barrel; a thermocouple in thermal communication with the barrel; anda heating controller in electronic communication with the heating deviceand the thermocouple; wherein the heating controller activates theheating device dependent upon an input signal received from thethermocouple; and an insulator located on an external side of thebarrel.
 3. The apparatus of claim 1 wherein the hopper furthercomprises: an upper hopper plate configured to carry the securingmechanism; a conical body having an upper aperture with a diametergreater than a diameter of the lower aperture, wherein the conical bodytapers from the upper aperture to the lower aperture; a lower flangesecured to the conical body of the hopper proximate the lower apertureof the conical body; and wherein the upper hopper plate occludes theupper aperture of the conical body.
 4. The apparatus of claim 3 whereinthe upper hopper plate further comprises: an air filter aperture formedthrough a thickness of the upper hopper plate adapted to carry an airfilter; and a sealable aperture formed through the thickness of theupper hopper plate and adapted to be in a sealed or an unsealedconfiguration.
 5. The apparatus of claim 1 wherein the nozzle furthercomprises: a tube defining a cavity and having an open end defining theupper aperture and an occluded end; and wherein the lower aperture ofthe nozzle is located in the occlude end of the tube.
 6. The apparatusof claim 1 wherein the fume extraction system further comprises a platesecured to the nozzle.
 7. The apparatus of claim 6 wherein the fumeextraction system further comprises: a plurality of tubes, wherein eachof the plurality of tubes has a first open end secured to the plate; amanifold carrying a second open end of each of the plurality of tubes;and an exhaust tube having a first open end secured to the manifold andin fluid communication with the second open ends of each of theplurality of tubes.
 8. The apparatus of claim 7 wherein the fumeextraction system further comprises: a cooling fan secured to the plateand in fluid communication with the lower aperture of the nozzle; and aduct boost fan secured to the exhaust tube and in fluid communicationwith an interior volume of the exhaust tube.
 9. The apparatus of claim 1wherein the barrel further comprises: a small cone having a sidewall, anupper aperture, and a lower aperture, wherein a diameter of the upperaperture is greater than a diameter of the lower aperture and thesidewall tapers from the upper aperture to the lower aperture; an upperflange secured proximate the upper aperture of the small cone andsecured to the lower flange of the hopper; and a pipe having a first endand an opposing second end secured proximate the lower aperture of thesmall cone, wherein the first end secures to the upper aperture of thenozzle.
 10. The apparatus of claim 9 wherein the barrel furthercomprises: a feed screw positioned in an interior of the pipe; a driveshaft adapted to transmit torque to the feed screw; a motor adapted toprovide torque to the drive shaft; and a motor controller adapted tocontrol the torque provided by the motor.
 11. The apparatus of claim 10wherein the barrel further comprises: an agitator; a flange located at afirst end of the drive shaft and secured to the agitator; and a ballbearing housing surrounding the drive shaft.
 12. A three-dimensionalprint head apparatus comprising: a hopper having a cavity and a loweraperture, the hopper being connectable to a robotic arm; a nozzle havingan upper aperture and a lower aperture; a barrel; a heating systempositioned along the barrel comprising an insulator located on anexternal side of the barrel; and a fume extraction system comprising: aplate secured to the nozzle; a plurality of tubes, wherein each of theplurality of tubes has a first open end secured to the plate; a manifoldcarrying a second open end of each of the plurality of tubes; and anexhaust tube having a first open end secured to the manifold and influid communication with the second open ends of each of the pluralityof tubes.
 13. The apparatus of claim 12 wherein the fume extractionsystem further comprises: a cooling fan secured to the plate and influid communication with the lower aperture of the nozzle; and a ductboost fan secured to the exhaust tube and in fluid communication with aninterior volume of the exhaust tube.
 14. The apparatus of claim 12wherein the hopper further comprises: an upper hopper plate an airfilter aperture formed through a thickness of the upper hopper plateadapted to carry an air filter and a sealable aperture formed throughthe thickness of the upper hopper plate and adapted to be in a sealed oran unsealed configuration; a conical body having an upper aperture witha diameter greater than a diameter of the lower aperture, wherein theconical body tapers from the upper aperture to the lower aperture; and alower flange secured to the conical body of the hopper proximate thelower aperture of the conical body; wherein the upper hopper plateoccludes the upper aperture of the conical body.
 15. The apparatus ofclaim 12 wherein the nozzle further comprises: a tube defining a cavityand having an open end defining the upper aperture and an occluded end,wherein the lower aperture of the nozzle is located in the occlude endof the tube.
 16. The apparatus of claim 12 wherein the barrel furthercomprises: a small cone having a sidewall, an upper aperture, and alower aperture, wherein a diameter of the upper aperture is greater thana diameter of the lower aperture and the sidewall tapers from the upperaperture to the lower aperture; an upper flange secured proximate theupper aperture of the small cone and secured to the lower flange of thehopper; and a pipe having a first end and an opposing second end securedproximate the lower aperture of the small cone, wherein the first endsecures to the upper aperture of the nozzle.
 17. The apparatus of claim16 wherein the barrel further comprises: a feed screw positioned in aninterior of the pipe; a drive shaft adapted to transmit torque to thefeed screw; a motor adapted to provide torque to the drive shaft; amotor controller adapted to control the torque provided by the motor; anagitator; a flange located at a first end of the drive shaft and securedto the agitator; and a ball bearing housing surrounding the drive shaft.18. The apparatus of claim 12 wherein the heating system furthercomprises: a heating device in thermal communication with the barrel; athermocouple in thermal communication with the barrel; and a heatingcontroller in electronic communication with the heating device and thethermocouple; wherein the heating controller activates the heatingdevice dependent upon an input signal received from the thermocouple.19. A three-dimensional print head apparatus comprising: a hopper havinga cavity and a lower aperture; a nozzle having an upper aperture and alower aperture; a barrel comprising: a feed screw positioned in aninterior of the pipe; a drive shaft adapted to transmit torque to thefeed screw; a motor adapted to provide torque to the drive shaft; and amotor controller adapted to control the torque provided by the motor; aheating system positioned along the barrel; and a fume extraction systemcomprising: a plurality of tubes, each having a first open end; amanifold carrying a second open end of each of the plurality of tubes;and an exhaust tube having a first open end secured to the manifold andin fluid communication with the second open ends of each of theplurality of tubes.
 20. The apparatus of claim 19 wherein the heatingsystem comprises: a heating device in thermal communication with thebarrel; a thermocouple in thermal communication with the barrel; and aheating controller in electronic communication with the heating deviceand the thermocouple; and an insulator located on an external side ofthe barrel; wherein the heating controller activates the heating devicedependent upon an input signal received from the thermocouple.
 21. Theapparatus of claim 19 wherein the hopper further comprises: an upperhopper plate configured to carry the securing mechanism; a conical bodyhaving an upper aperture with a diameter greater than a diameter of thelower aperture, wherein the conical body tapers from the upper apertureto the lower aperture; a lower flange secured to the conical body of thehopper proximate the lower aperture of the conical body; and wherein theupper hopper plate occludes the upper aperture of the conical body. 22.The apparatus of claim 21 wherein the upper hopper plate furthercomprises: an air filter aperture formed through a thickness of theupper hopper plate adapted to carry an air filter; and a sealableaperture formed through the thickness of the upper hopper plate andadapted to be in a sealed or an unsealed configuration.
 23. Theapparatus of claim 19 wherein the nozzle further comprises: a tubedefining a cavity and having an open end defining the upper aperture andan occluded end; and wherein the lower aperture of the nozzle is locatedin the occlude end of the tube.
 24. The apparatus of claim 23 whereinthe fume extraction system further comprises: a cooling fan secured tothe plate and in fluid communication with the lower aperture of thenozzle; and a duct boost fan secured to the exhaust tube and in fluidcommunication with an interior volume of the exhaust tube.
 25. Theapparatus of claim 19 wherein the barrel further comprises: a small conehaving a sidewall, an upper aperture, and a lower aperture, wherein adiameter of the upper aperture is greater than a diameter of the loweraperture and the sidewall tapers from the upper aperture to the loweraperture; an upper flange secured proximate the upper aperture of thesmall cone and secured to the lower flange of the hopper; and a pipehaving a first end and an opposing second end secured proximate thelower aperture of the small cone, wherein the first end secures to theupper aperture of the nozzle.
 26. The apparatus of claim 19 wherein thebarrel further comprises: an agitator; a flange located at a first endof the drive shaft and secured to the agitator; and a ball bearinghousing surrounding the drive shaft.